Swamps I have Known

I like swamps. I must be easily amused. Or maybe it's oddly amused. Either way, it must come with getting older because I don't remember thinking this way when I was younger. One of the reasons that I like the Hemlock Forest is that the area contains several different wetland types. Still, when you come right down to it those areas are pretty similar. So along with the swamps and bogs of the Hemlock Forest I've been visiting a larger (and wilder) swamp found in the central Adirondacks just east of Long Lake - what I call the Shaw Pond Swamp (not sure if there is a more official name). I've also made a couple of trips to Lincoln Mountain State forest just outside of Saratoga Springs. The Lincoln Mountain forest covers about 1000 acres and it contains a less common swamp ecosystem; a red-maple black-gum swamp. I'll be writing more about these areas in future posts but for now some photos will have to suffice.

Dec. 24th 2013 near the margin of the Shaw Pond Swamp.

The area includes Shaw Pond, which is not far being a swamp itself.  The "swamp" includes a progression of bogs and swamp habitats of various types. View the Map in Google Maps.

The USGS Togopgraphic map of the area names Shaw Pond and Shaw Brook. Access is from the trail leaving NY Route 28 just east of Long Lake. This is the Northville-Lake Placid Trail so the trail goes both north and south from the parking lot. The swamp is a quarter mile south of the parking area.

Early winter is a good time to explore Adirondack wetlands.

The open swamp is visible here through the trees. There is a large area of flooded forest. (12/24/2013)

Back at home, looking at photos and working from memory I've been trying to figure out what kind of swamp this is. I think that it is a Larch Swamp but I need to go back and verify that. The value of taking good notes cannot be overemphasized.

Beaver are rarely faulted for a lack of ambition. Beaver have damned Shaw Brook just below the bridge the NTP crossing. As of Dec. 2013 the bridge is passable. That won't be the case if the water backs up much further.

Same area, the day before the dusting of snow seen in the photos above (12/23/13).

Same area in October of 2013.

Lincoln Mountain State Forest

Lincoln Mountain State Forest from Google Earth

One of several boggy ponds at Lincoln Mountain State Forest

A boggy flooded forest at Lincoln Mountain State Forest

The same swampy area as above from a different vantage point

Data: Bittersweet

You can't talk about invasive plant species in this part of New York State and not talk about Asiatic Bittersweet (AB). This vine is one of the most visible and damaging of the invasive species found in the Hemlock Forest. I know a little more about the specifics of this plant because about 10 years ago it appeared in my backyard. I've been battling it there ever since. I cut it off at the ground and I pull it out by the roots. I've fought AB to a draw in my yard but it is everywhere in the surrounding area; especially in a successional field near my house where it has pulled down several trees by the sheer weight of the vines. AB spreads both by the dispersal of seeds by birds (that eat the berries) and via rhizomes that spread out from every established vine. This plant is not going away anytime soon.

Image One: A dense cluster of Asiatic Bittersweet vines in the Hemlock Forest.

Asiatic Bittersweet is not a shy plant and even in a dense forest spotting the vine is easy. It wraps itself tightly around the trunks of trunks of trees and it will bridge from tree to tree in the canopy. But it is in the late fall and winter that AB really stands out. Mature plants produce large quantities of orange-red berries with yellow sheaths that are quite distinctive. The only plant you might confuse it with is its native cousin, American Bittersweet. Asiatic Bittersweet hybridizes with the native variety and by all accounts the hybrid is quickly replacing the native version everywhere that both species are present. Unfortunately, the hybrids appear to take on the negative characteristics of the invader. Namely, it's ability to produce a mass of vines that tend to strangle whatever it gets a hold of. The native variety is certainly not extinct, so before you take actions to control this plant be sure you know which one you are looking at. The plants are very similar in appearance with one easily spotted distinction. When berries are present, if the berries are found all along the vine it is Asiatic Bittersweet. The berries of the native variety appear only at the very ends of each vine.

AB will be one of the plants I focus on in studying the invasive species present in the Hemlock Forest. The general questions I've discussed in other posts certainly apply and, in the case of AB, there is the additional issue of why the non-native variety is so much more destructive than the native species. In the Hemlock Forest AB is found pretty much everywhere there is an opening in the canopy. There are several old fields in various stages of succession in the forest and AB is present in all of them. It is almost certainly present in other places in the forest as well and one of my first goals will be to map the full extent of its' presence. That data can be used in the future to learn more about how AB disperses. AB can also be used to study how community assemblages are changed by a well established and aggressive invasive species.

Map One: The purple polygons show areas where Asiatic Bittersweet is present in significant quantities. This highly aggressive vine is probably found in other parts of the forest but I have not yet specifically mapped its' presence.


References and Resources:
Asiatic Bittersweet (Wikipedia)
Mistaken Identity: Invasive Plants and their Native Look-alikes

Base Maps

In earlier posts I introduced the Hemlock Forest area and I talked about why I want to understand how ecological communities are changed when non-native species become fully established (look back at those previous posts for the details). I've also said that anyone with motivation can acquire and contribute valuable scientific data. What I have not talked about is what data you might get and how you might get it. The what and how will vary based on your interests but the thing I can do is to describe my project in detail. If you extrapolate from there.

As for the "what" you have to start with a question; something that interests you. I want to understand how non-native species alter existing ecological communities and species assemblages. My thinking is that in many cases these aggressive non-native species are not going away. They are here to stay. So, at what point do the invaders alter previously existing communities to an extent that a new community type is present. Most importantly, are those new assemblages of species more or less fit in terms of their capacity to provide ecological services and to resist future disruptions. It's commonly held that the general reason invasive species are so successful is that predators and pathogens that co-evolved with the invader are not present in a new locale. That is certainly part of the story but I wonder if some species are in effect "generalists" able to dominate where ever they are found. Take Japanese Knotweed for example. Once established, you can repeatedly mow a stand of Japanese Knotweed off at the ground for several years running and it will grow back with vigor as soon as you stop. And, if you are not paying attention, it will spread to surrounding un-mowed areas via rhizomes. Eventually you can kill it by depleting the energy reserves present in the roots, but Japanese Knotweed is one tough plant. Human activities have increased the speed at which plants like Japanese Knotweed are dispersed but it seems possible that this plant has evolved strategies that would allow it to spread far and wide on its own. We need to better understand how these aggressive generalist species operate because it seems likely that they will eventually be present globally where ever there is suitable habitat.

Back to the project, the first thing I want to know is which communities are present and where they are located. This is the easy part for me because my interest in this has emerged from working with geographic information systems (GIS). A GIS allows you to place your data into a geographic context. Using a GIS you can visually look for patterns in the distribution of the phenomena of interest. Going further, there are a wide variety of analysis techniques you can use to learn more about the phenomena as represented by your particular set of data. In short, I am starting the project with the creation of a GIS.

The first thing you need are base maps. As a term, "base-maps" doesn't have a distinctly defined meaning. It refers to whatever map layers are needed to put your data into a geographic context. These days we can download a wide variety of base-map layers from the Internet. Believe me, it didn't used to be that easy. And, if you are working outside of the United States, it might still be a major undertaking to get the base-map layers that you need. For my project I'm starting with a raster base-map layer created from a USGS topographic map. The USGS refers to these as digital raster graphics or DRGs. I'll be writing about where you can get map layers of various types in future posts but, for now I'll let the images tell the story.

A digital raster graphic (DRG) base layer showing the hemlock forest. The red line delineates the boundary of the land that is included in the Saratoga Spa State Park. The orange line shows the marked trails coming from the parking area on Crescent street (upper right in the image). Notice that in the lower left portion of the image the red boundary line does not follow the boundary visible in the underlying DRG. The boundary line was digitized from a map of the State Park and there is a slight discrepancy between the two sources. This could be the result of the two sources using different surveys or it could be a cartographic discrepancy coming from differences in the scale and accuracy represented by the two different sources.

I have also acquired aerial imagery of the Hemlock Forest Area; orthoimagery made available for public use by the New York State GIS Clearinghouse (see the Mystery Lines post for more information on this imagery source). The images are geo-registered and line up pretty well with the underlying topographic map layer. My data will be layered on top of the background provided by the DRG and the orthoimagery and I've started by creating a layer containing the park boundary and the state maintained trails present in the forest.

Image Two: The Hemlock Forest aerial image base layer with park boundary (red) and trails (orange) superimposed. Many details emerge from this view of the forest. For one, the old growth hemlocks that provide the area's namesake are easily seen clustered in the area circled by the upper trail loop.   

My interest is in ecological communities so I need to know what communities are present and where they are located. That information is available in a map published along with the Spa State Park Master Plan released in 2009. The ecological communities map is provided as an image in a PDF file. You can't add this PDF to the GIS directly but I was able to take the image and register it with the base maps in my GIS. I'll document the process used to do that in a future post but images three and four show the results A key feature of the GIS software is that it allows you to control the level of transparency used to display each layer.

Image Three: The ecological communities map registered in the GIS. I grabbed the image from the PDF using standard screen capture software. The screen capture was saved to a JPEG format image file. That file was added to the GIS and registered with the base-map layer. As seen here, the ecological communities layer is displayed as a non-transparent layer; you can't see through it but you can see the base layers around the edges. The boundary and trail outlines are visible because that layer is displayed on top of the eco-communities layer. Each colored area represents a different community type and the zones can be interpreted using the legend found in the original document. 

Image Four: The same map with the eco-communities layer set be partially transparency. Now we can see through the eco-communities layer to the underlying imagery. Using the GIS in this way each additional layer provides more information and seen in combination patterns that were not previously visible become apparent.

There's one more layer that I need for may base layer set. That is a layer of just the outlines of the community zones created in a way that will allow a database table row to be linked with each zone. This linkage between map objects and data is what GIS is all about and this capability will provide the basis for future analysis. I created the layer by "hand digitizing" the ecological community image; essentially I traced the outlines of the zones using tools provided in the GIS. The window seen in Image Five shows data associated with the object selected in the map (the blue area in the center). I'm just getting started, so I have only a couple of columns in the database table. But now that the linkage is in place I can add more columns as I need them.

Image Five: The complete base-map set from the GIS. The black outlines are the zonal boundaries for the various ecological communities identified in the Spa State Park master plan. Each outlined object is linked to a row in a database table. This allows the map representation of each ecological community to be associated with whatever data we want to capture.

Reference and Resources:
The Spa State Park Master Plan Eco-communities map

The Project - The Effect of Invasive Plant Species on Native Ecological Communities

I'm interested in systems. That includes computer systems; hence my day job as a software developer. But beyond earning a living, I've long been interested in complex systems and how information is represented within those system. This may be where my fascination with ecosystems and ecological communities comes from. Of course, it's also true that I just like to tramp through forests, fields and swamps so maybe that's it.

Recently I've been thinking about how ecological communities adapt to rapid change. Ecological communities are defined by combinations of plants and animals found in a specific environmental context. The Hemlock Forest contains a half dozen or so different community types (see the NYS Natural Heritage Ecological Communities Site) with names like, "Hemlock-Hardwood Swamp" and "Appalachian Oak-Pine Forest". At the scale of an ecological community rapid change can result from events such as a fire or from someone digging a ditch to drain a wetland. Or it can unfold more slowly such as when an aggressive non-native species becomes established in an area altering the established mix of plants and animals. Rapid changes unfold on time scales that we can see; a day, a month, a few years. But even change that takes place over a decade or two is barely a smidgen of an instant in terms of geologic or evolutionary time scales. From the perspective of geologic time, humanity is altering the ecological systems on the earth at a pace that resembles a great natural cataclysm. Much like when that famous asteroid struck and killed the dinosaurs or when a super volcano explodes and alters the composition of the atmosphere. We are running a gigantic experiment on the earth's systems by rapidly altering ecosystems at every scale.

Ecologists study these sorts of things but the pace and scale of the changes taking place now far outpace their (our) capacity to understand what is happening. We have put into motion changes that will produce a range of effects that future generations will have to deal with and our children and grand-children will probably be forced to manage and repair natural systems in ways that we really can't imagine (did you grandparents imagine the world we live in today?). To do that they will need to know as much as possible about how these systems worked before we messed around with them. Information is the key and our technologies, the same ones that have the potential to be our undoing, might also save us. These days, anyone with motivation can add to the data that might really matter to those working on these problems in the future.

Of course, access to tools doesn't mean that acquiring useful data is simple or obvious. What data is valuable? How do you actually get it? How do you manage it? These are among the questions that motivated me to create this blog. I don't have all the answers but maybe I can add something that is part of the solution. Whatever you figure out, please share. Unlike most ecosystems I can adapt rapidly when a better idea comes along.

The Plan

I live in the northeastern United States where some of the most interesting ecological communities are the wetlands: swamps, marshes, fens, bogs and so on. The Hemlock Forest area contains several different wetland community types in close proximity to each other. Image One shows a flooded forest (more formally a Red Maple Hardwood Swamp). Image Two shows a Perched, Swamp White Oak, Swamp. It's a perched swamp (the defining environmental characteristic) dominated by the Swamp White Oak (species). Interestingly, this community type is considered to be rare in New York State. It's not that the individual species are rare --Swamp White Oaks are fairly common-- but the perched swamp environment has brought together an uncommon combination of species. Image three shows a third wetland type present in the Hemlock Forest; your basic Hemlock-Hardwood Swamp.

Image One: The Hemlock Forest includes several different types of wetlands. The area pictured is a Red-Maple Hardwood Swamp - often referred to as a flooded forest. The species mix present in this area has been altered by the rapid spread of non-native plants and shrubs and also by past attempts to drain the swamp.

Image Two: The Perched, Swamp White Oak, Swamp area. It is a perched swamp because the surface water is disconnected from the water table by a layer of impermeable clay. The characteristic species is the Swamp White Oak; The large tree on the left is a Swamp White Oak.

Image Three: The forest contains numerous small Hemlock-Hardwood Swamps. The trees in the foreground are Hemlocks and the entire forest area is named after the stand of old growth hemlocks present in the northern half of the preserve.

The varied ecological communities present in this 300 acre forest make it appealing as a place to learn more about how ecological communities adapt to the introduction of aggressive non-native species. I've focused on plants and shrubs because they are relatively easy to identify and the Hemlock Forest area has significant populations of several non-native shrubs and vines including:

• Asiatic Bittersweet (Image Four)
• Japanese Barberry
• Burning Bush
• Japanese Knotweed

Image Four: A tangle of Asiatic Bittersweet vines. This aggressive invader is present throughout the forest where ever there is a break in the canopy.

Other invasive plants, shrubs, and trees (and creatures of various types) are present but these four spread rapidly and alter the composition of existing native communities. This raises additional questions, including:

• Why are these species so successful? Not all introduced species out-compete natives species or spread so rapidly
• To what extent, and how quickly, do native species adapt to these newcomers?
• Do non-native species alter established patterns of succession within native community types?
• Are there effective control methods for these species? And, if the makeup of a community has been altered by the established presence of non-native species, what effects might come from "controlling" the invader(s)? In other words, can "controlling" the invading species make matters worse?

These are bread-and-butter questions for ecologists and these plants have been studied extensively. Still, answers to these questions commonly start with, "It's unclear" or "It depends...". It depends on which invasive you are talking about and it depends on which ecological community type has been invaded. Asiatic Bittersweet (AB) is present in the forest where ever there is a break in the canopy. It is found along the margins of wetland areas and in successional areas used in the past for agricultural. But what about isolated breaks in the canopy such in the small marsh located near the center of the forest? I have not yet spotted any AB there. That marsh does contain Japanese Barberry, and quite likely other non-native wetland invaders, but why no AB? Is there something about the ecology of the marsh or is it simply that AB had not yet spread to that location?

There are many unknowns around how native communities adapt to species that suddenly appear on the scene. And that is the basis for my assertion that anyone can do important research by capturing data about these communities. The key is the use of methods that preserve the meaning of the data for the long term.

My project is based on an assumption that well established non-native species are part of a new norm for these communities. In other words, we may need to define new communities that incorporate the presence of these species. With that as a starting point I want to know whether newly adapted communities will be more or less resilient in the face of future changes. And these questions go well beyond new plant species appearing in swamps that few people ever see. Ecological changes also alter the mix and behaviors of non-plant species including friendly insects such as ticks and mosquitos. I grew up running and playing and tramping through forests and fields and swamps and ticks were almost never seen. A word of warning that if you visit the Hemlock Forest area, you need to take precautions against the deer ticks (Brown Legged Ticks) that carry Lyme disease. These little critters are very common and very friendly. The paper referenced in this article proposes that greater bio-diversity reduces the spread of parasitic disease and we are reducing biodiversity at a pace and scale that has rarely occurred in the past (the deep past, millions of years).

This post is a lot longer than I had intended but there you have it; the what and why; next up, the how.

References and Resources
Landscape Ecology (Wikipedia)
Study Shows How Biodiversity can Protect Against Disease